✦ LIBER ✦
Electronic effects in some 3-substituted-2-cyclohexenones: A study by carbon-13 n.m.r. spectroscopy
✍ Scribed by G. R. Bedford; P. J. Taylor
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 356 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The carbon‐13 n.m.r. spectra of some 3‐substituted‐2‐cyclohexenones show very wide variations in chemical shift at C‐3 that correlate with Pauling electronegativity χ, even wider variations at C‐2 that correlate with the Taft resonance parameter σ~R~º and almost no variation at C‐1. These very different effects are shown to be consistent with the electronic distribution for these and related compounds revealed by other spectroscopic techniques. Reasons for the insensitivity of carbon‐13 n.m.r. to configurational and conformational variation in simple enamino‐ketones are discussed.